textproduct: Rapid City

KEY MESSAGES

- Near-critical to critical fire weather conditions expected Wednesday through at least Friday.

- Cooler Tuesday with above average temperatures (10F+ above normal) for the latter half of the week.

UPDATE

Issued at 945 PM MDT Mon Aug 31 2026

Going forecast in good shape. Water vapour loop depicted shortwave over UT, which will slip northeast overnight into Tuesday bringing modest 800-600mb theta-e advection and a slug of moisture. Result will be a cluster of shra/TS through midday and then isolated strong/severe thunderstorms over south-central SD Tuesday afternoon. Temperatures will be tricky Tuesday given precipitation/cloud cover, so stuck with guidance. Then, very warm to hot and mostly dry into next weekend.

DISCUSSION

(This Evening Through Monday) Issued at 100 PM MDT Mon Aug 31 2026

Water vapor imagery shows upper low centered over eastern Saskatchewan and western Manitoba with southwest flow across the western half of the country. Shortwave trough and mid- level moisture plume is evident over the Four Corners region. Surface low pressure is centered over southeastern Saskatchewan with a cold front stretching from northern MN through western IA.

Cooler today (80s-90 on the plains with 70s to near 80 in the Black Hills) and dry with elevated fire weather the main concern. Water vapor imagery highlights upper level moisture pushing into the southern forecast area ahead of the shortwave trough to our southwest. This wave will bring showers and storms to the area late tonight/early Tuesday morning through Tuesday afternoon. While widespread severe weather is not expected, a few strong to severe storms are possible across south-central SD into south- eastern SD Tuesday.

Upper level ridge will build across the Northern Plains Wednesday through the end of the week with much hotter and drier weather. Highs will push into the 90s to near 100 by Friday (on the plains). Stronger southerly winds will develop during this time, resulting in near-critical to critical fire weather conditions Wednesday through at least Friday.

AVIATION

(For the 06Z TAFS Through 06Z Tuesday Night) Issued At 927 PM MDT Mon Aug 31 2026

A band of showers with embedded thunder will move through the area after 01/09z, persisting through much of Tuesday as the precipitation moves northeast. Isolated MVFR conditions may occur, especially over south-central SD. Otherwise, VFR conditions will prevail through the forecast period.

FIRE WEATHER

Issued At 100 PM MDT Mon Aug 31 2026

Elevated fire weather conditions today across the area with daytime RH falling into the teens, although winds will generally remain below critical levels. Precipitation chances return for southern into south-central SD late tonight into Tuesday ahead of much warmer weather to end the week.

Temperatures will warm into the upper 80s to low 90s Wednesday with even hotter temperatures Thursday and Friday as RH falls into the teens; near single digit RH possible across portions of far SW South Dakota into NE Wyoming Thursday and Friday where south-southwest winds will gust 25 to 30 mph.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.